Inside One Winery's Quest for Sulfite-Free Wine—What It Means and Why It Matters

It's one the world’s most important elements, and it's practically ubiquitous in wine. But some wine drinkers blame it for headaches. You know it from the "contains sulfites" warning that must, by law, appear on any bottle of wine containing 10mg per L or more of the stuff. Added to most wine in either a liquid or powder form to help snuff out bacteria or microbes that could lead to spoiling, it's actually the only ingredient in wine that producers are required to name. It's sulfur dioxide (SO2), and it's facing a reckoning.

More and more, winemakers are experimenting with low-sulfite or sulfite-free wines, which tend to be categorized as “natural” or “low-intervention,” because of the lack of additives. But the exclusion of some or all sulfites must not be confused with the broader umbrella terms. As Master of Wine Isabelle Legeron, author of , and one of the foremost experts on natural wines, points out, “Natural wines are (and have always been) wines that are farmed using organic and biodynamic practices and made with the most minimal intervention possible, including being sulfite-free.” But she cautions that “while ‘organic,’ ‘biodynamic,’ ‘low-intervention,’ and ‘natural’ are all buzzwords in the sulfite-free world, they all mean different things and are not interchangeable.”

Just ask Jared and Tracey Brandt, the husband and wife duo behind , whose wine I first encountered five years ago in Los Angeles thanks to natural-wine proponent Lou Amdur. From lush, complex, vibrant and interesting whites, to elegant, perfumed and sometimes funky reds, with the token pét-nat in between, Donkey & Goat wines offer something for everyone, and no two bottles are alike. The Brandts are two of California’s biggest proponents of low-sulfite wines, but there's more to their mission than meets the eye—or bottle.

In 2001, Jared left a lucrative technology job, and with Tracey, jumped the pond to work for free for a French winemaker named Éric Texier. “My kids would look at the floppy disks on my desk, and wonder what the hell they were,” he explains, “So, I wanted to do something real.”

Texier, a former material scientist specializing in carbon fiber based in the Rhône Valley, is a big proponent of low-sulfite wines, and laid the foundation for what would eventually become Jared and Tracey’s raison d’etre in winemaking.

The couple returned to the States in 2003 and produced their first wines—just 10 barrels in a basement in San Francisco. In 2004, they moved into a bonded winery facility in a shared space in the city’s Potrero Hill neighborhood. Since then, they've moved their urban winery to an old, industrial warehouse in Berkeley, California, and that's where you can find them now. Step inside, and you'll instantly see how the thick, concrete walls help keep the place impressively cool, even during the hottest summer days.

Kelly J Owen

After 15 years in the biz, and lots of experimentation—going from no sulfur additions to minimal sulfur, for one—the couple's style has evolved. So, as the debate over—and misinformation about—sulfite-free wine continues to rage, I sat down with Jared and Tracey to check in on how they've grown with the movement, and where they see it going.

“I don’t think our styles have changed much,” Jared tells me, but “we’ve become better winemakers. There’s a lot of little things we’ve gotten better at fine-tuning. When we started out, we didn’t inoculate with yeast to start fermentation, we didn’t do any sulfur additions—we let the wine be what it was going to be. We struggled on low-sulfur wines and even had a few sulfur-free disasters. As we evolved, we moved away from no sulfur, but we are gradually going back.”

Brandt says that the biggest change has occurred in how they farm their vineyards. They used to pick early, when sugar-levels were lower, which would result in lower-alcohol wines. But today, they “try to forget about numbers and try to focus on flavors,” he says. “When we started out, we got told our wines were ‘wimpy’ at 13.5 percent alcohol, but the dogmatic approach to having low-alcohol wines isn’t much different than the dogmatic approach to making high alcohol wines.”

Really, making great wine is all about achieving balance. “Every year is different, every vintage is different, and balance takes on a different meaning—some years the grapes need longer hang time.”

Here, Jared hits the nail on the head. Proponents of low-sulfite or sulfite-free wines are highly attuned to balance. Because they strive not to add or remove anything at all from their wines, astute microbial management is critical to not losing everything. The biggest risk is that a wine could referment, or become unstable after bottling. Jared has had his share of mishaps, and if he suspects a wine could become unstable, he’s willing to add SO2 as a safeguard. Wines with low acidity are most susceptible to becoming unstable, and adding SO2 essentially guarantees a stable wine.

As he explains, “I’m not dogmatic against sulfur. I’ve been experimenting with it for years. The biggest thing for me is to put ingredients on our labels.”

Pointing to a bottle on the table, he says, “that one was easy because it was just the grapes,” and had sulfites at such low levels, he didn’t have to include a note on the label.

But it's not as simple as choosing to add or omit additional SO2. Jared has tested wines from winemakers who claim to use no added sulfites, and when he measured the wine—the numbers were high. "You wonder, where did all the sulfur come from?”

The answer, Jared believes, lies in the release of “bound sulfur.” After cleaning an oak barrel, some winemakers will burn a sulfur candle to fully kill any bacteria that might cause mold. “I think some of that sulfur remains,” he says, adding, “I’ve noticed in general that whites that are barrel-fermented tend to pick up sulfur, and if we do stainless steel-aging, they don’t pick up as much. If you’re farming organically, you’re spraying your vineyard with sulfur and that bound sulfur prob gets released into the grapes—I’ve never tested straight unfermented grape juice for sulfur. Maybe I’ll do that next.”

In his own experimentation, Jared has found sulfur where he didn't expect it, and none when he did. “I have a sulfur-free, biodynamic vineyard where we don’t use any copper-sulfate (a powdery grape fungicide), or any sulfur at all; we do add a specific amount of sulfur, but testing it reveals varying levels in the finished wines. We also have no-sulfur wines, which even after using sulfur in the vineyards, ended up with no measurable sulfur.”

He's wondering what will happen if they change vessels, which could ultimately have big implications, if, say, they find that concrete or wood containers preclude sulfite-free wine. That could mean losing barrel-complexities, or the freshness winemakers love from fermenting in concrete. Whatever they find, for Brandt, it's all about transparency—if there's anything dogmatic about the approach at Donkey & Goat, it's that.

When I ask him the question everyone wants to pose—what about the headaches?—he laughs.

“I think writers should give up on saying that sulfur doesn’t cause headaches. My response is, anytime you want to come over here and snort some metabisulfite, you’re going to get a headache. Probably the worst headache of your life and you’ll probably end up in the emergency room before it's done. Sulfur clearly has impacts on the body. But is it just that some people are drinking too much? Maybe." He adds, "It’s a really complex equation and people being dogmatic about no sulfur are just as silly as those who say it doesn’t matter.”

Tasting Notes

2017 Donkey & Goat Red Wine Gigi, Sans Soufre El Dorado ()

Unfined and unfiltered with just 11.7% alcohol, this Syrah had no sulfur additions and is fresh and vibrant with cracked white pepper, violet notes, and gobs of delicious red-berry fruit flavors. Juicy and long on the finish.

2017 Donkey & Goat Mourvèdre Twinkle El Dorado

Unfiltered and clocking it at a low 11.4 percent alcohol. Beautiful pale ruby hue, with crushed raspberries, cranberries, and feathery tannins, giving way to a subtle cocoa-nib finish.

2017 Donkey & Goat Pinot Gris Ramato Filigreen Farm Anderson Valley While no sulfur is used in the vineyard, the wine sits on its skins in concrete for five days and finishes fermenting in oak, which may release some bound sulfur. At 11 percent alcohol, it’s an easy quaffer, with a generous mouthfeel, ample acidity and redolent of crushed herbs and melon, tinged with sea-spray minerality.